DISCOVERY OF GAMMA-RAY EMISSION FROM THE SHELL-TYPE SUPERNOVA REMNANT RCW 86 WITH HESS

The shell-type supernova remnant (SNR) RCW 86, possibly associated with the historical supernova SN 185, with its relatively large size (about 40' in diameter) and the presence of non-thermal X-rays is a promising target for gamma-ray observations. The high sensitivity, good angular resolution of a few arc minutes and the large field of view of the High Energy Stereoscopic System (H.E.S.S.) make it ideally suited for the study of the gamma-ray morphology of such extended sources. H.E.S.S. observations have indeed led to the discovery of the SNR RCW 86 in very high energy (VHE; E > 100 GeV) gamma-rays. With 31 hours of observation time, the source is detected with a statistical significance of 8.5 sigma and is significantly more extended than the H.E.S.S. point spread function. Morphological studies have been performed and show that the gamma-ray flux does not correlate perfectly with the X-ray emission. The flux from the remnant is ~10% of the flux from the Crab nebula, with a similar photon index of about 2.5. Possible origins of the very high energy gamma-ray emission, via either Inverse Compton scattering by electrons or the decay of neutral pions produced by proton interactions, are discussed on the basis of spectral features obtained both in the X-ray and gamma-ray regimes.

HESS Collaboration F. Aharonian | et al | A. R. Bazer-Bachi | K. J. Orford | Nicolas Produit | T. Bulik | E. Moulin | T. Lohse | T. Mccomb | M. Kerschhaggl | W. Domainko | W. Benbow | S. Rosier-Lees | A. Quirrenbach | J. Olive | D. Emmanoulopoulos | M. Renaud | C. Venter | M. Raue | F. Dubois | S. Ohm | C. Stegmann | J. Vink | W. Hofmann | M. Hauser | R. Schlickeiser | L. Chounet | F. Aharonian | D. Horns | Y. Gallant | K. Kosack | F. Feinstein | P. Goret | M. Naumann-Godo | A. Santangelo | L. Drury | S. Gabici | S. Wagner | M. Beilicke | J. Ruppel | M. Vivier | C. Farnier | D. Khangulyan | H. Dickinson | J. Ripken | J. Tavernet | M. Panter | B. Behera | K. Bernlöhr | C. Boisson | I. Braun | A. Djannati-Ataï | G. Dubus | J. Dyks | K. Egberts | A. Fiasson | A. Förster | L. Gérard | B. Giebels | J. Glicenstein | G. Henri | G. Hermann | A. Jacholkowska | I. Jung | K. Katarzyński | B. Khélifi | N. Komin | G. Lamanna | J. Lenain | A. Marcowith | R. Moderski | D. Nedbal | J. Niemiec | S. Nolan | M. Ostrowski | G. Pedaletti | P. Petrucci | S. Pita | G. Pühlhofer | M. Punch | F. Rieger | L. Rob | B. Rudak | V. Sahakian | U. Schwanke | S. Schwarzburg | S. Schwemmer | H. Sol | R. Steenkamp | R. Terrier | O. Tibolla | G. Vasileiadis | J. Vialle | P. Vincent | A. Zech | L. Costamante | V. Borrel | B. Degrange | G. Fontaine | M. Lemoine-Goumard | P. Tam | E. de Oña Wilhelmi | G. Rowell | R. Chaves | V. Marandon | P. Chadwick | S. Kaufmann | Ł. Stawarz | J. Hinton | A. Akhperjanian | A. Bochow | J. Brucker | R. Bühler | I. Büsching | T. Boutelier | A. Charbonnier | A. Clapson | M. Dalton | P. Espigat | B. Glück | D. Hauser | A. Hoffmann | S. Hoppe | D. Keogh | O. Martineau-Huynh | D. Maurin | M. de Naurois | D. Nekrassov | G. Pelletier | B. Raubenheimer | S. Rayner | F. Schöck | A. Shalchi | J. Skilton | G. Superina | C. van Eldik | H. Völk | F. Volpe | S. Carrigan | C. Hadjichristidis | M. Holleran | I. Latham | C. Masterson | A. Zdziarski | J. Osborne | G. Heinzelmann | E. Brion | E. Kendziorra | O. C. de Jager | D. Spangler | R. Schröder | C. Medina | T. Lohse | M. Ward | U. B. de Almeida | M. Füssling | J. M. Martin | J. M. Martin | É. Brion | S. Wagner | K. Orford

[1]  Felix Aharonian.  Observations of the Crab Nebula with H.E.S.S , 2006 .

[2]  Aya Bamba,et al.  The X-Ray Synchrotron Emission of RCW 86 and the Implications for Its Age , 2006 .

[3]  J. A. Hinton,et al.  The status of the HESS project , 2004 .

[4]  Werner Hofmann,et al.  Status of the H.E.S.S. project , 2003 .

[5]  D. Helfand,et al.  An X-ray study of the remnant of SN 185 A.D. , 1984 .

[6]  R. Sato,et al.  A Suzaku Observation of the Low-Ionization Fe-Line Emission from RCW 86 (Special Issue: First Results from Suzaku) , 2007 .

[7]  H. J. Voelk,et al.  Magnetic field amplification in Tycho and other shell-type supernova remnants , 2005 .

[8]  X-RAY SYNCHROTRON-EMITTING Fe-RICH EJECTA IN SUPERNOVA REMNANT RCW 86 , 2002, astro-ph/0208013.

[9]  Felix Aharonian,et al.  Energy spectra of gamma rays, electrons, and neutrinos produced at proton-proton interactions in the very high energy regime , 2006 .

[10]  D. A. Green,et al.  The historical supernovae , 2003, astro-ph/0301603.

[11]  Sebastian Funk,et al.  Primary particle acceleration above 100 TeV in the shell-type supernova remnant RX J1713.7-3946 with deep HESS observations , 2007 .

[12]  U. Hwang,et al.  Search for X-ray evidence of cosmic ray acceleration in SNR shocks , 1999 .

[13]  H. Krawczynski,et al.  The optical system of the H.E.S.S. imaging atmospheric Cherenkov telescopes. Part I: layout and components of the system , 2003, astro-ph/0308246.

[14]  E. al.,et al.  Observation of VHE gamma-rays from Cassiopeia A with the MAGIC telescope , 2007, 0706.4065.

[15]  et al,et al.  H.E.S.S. Observations of PKS 2155-304 , 2004, astro-ph/0411582.

[16]  M. Holler,et al.  Observations of the Crab Nebula with H.E.S.S , 2005 .

[17]  Heinrich J. Völk,et al.  Theory of cosmic ray production in the supernova remnant RX~J1713.7-3946 , 2006 .

[18]  S. Funk,et al.  Background modelling in very-high-energy gamma-ray astronomy , 2006 .

[19]  A. Bamba,et al.  Discovery of Non-Thermal X-Rays from the Shell of RCW86 , 2000, astro-ph/0007365.

[20]  R. Yamazaki,et al.  A Spatial and Spectral Study of Nonthermal Filaments in Historical Supernova Remnants: Observational Results with Chandra , 2004, astro-ph/0411326.

[21]  A. Noutsos,et al.  Calibration of cameras of the H.E.S.S. detector. , 2004, astro-ph/0406658.

[22]  Inverse Compton emission from galactic supernova remnants: effect of the interstellar radiation field , 2006, astro-ph/0607344.

[23]  J. Rho,et al.  Thermal and Nonthermal X-Ray Emission in Supernova Remnant RCW 86 , 2000, astro-ph/0006149.